Virtual Thermostat

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1

Can someone sanity check me?

I want to use a virtual thermostat device for some automation. I simply want to use it so I can set a heating and cooling set point and then use that to drive some logic using WebCore.

Here's the issue:

I can't set the cooling set point any lower than two degrees above the heating set point. I guess this is to be used when you want the temperature between two points an upper and a lower. I don't need this, I want to use the virtual thermostat to allow me to automate a hot tub. I want the lower temp at 8 degrees (I live with Wim Hoff) and the upper at 38.

Any ideas?

2

What do you think would happen if a thermostat were in "Auto" mode with the cooling set-point at 8 degrees and the heating set-point at 38 degrees?

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3

The virtual thermostat device is intended to work like a real-world thermostat that controls some type of HVAC system with heating and/or cooling modes (or an auto mode that can switch between the two, typically in climates that experience “shoulder” seasons when cooling during the day and heating at night is the goal).

So if you want to control the temperature of a pool by turning its heater on/off, you’ll need to use a different tool.

Basic rules or rule machine can turn a switch on and off based on an any arbitrary upper and lower temperature thresholds you configure.

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4

IIRC I have a ‘ remote MQTT virtual thermostat’ driver that has no smarts at all inbuilt. It is just essentially an attributes store for thermostat settings. It was used to allow a remote (MQTT) thermostat to be integrated in HE. Whether it enforces cooling setpoint to be higher than heating I would have to check but that could be easily altered.

If you think that may be of use to you let me know . It’s part of the MQTT beta 3e distribution but I don’t think it’s reliant on MQTT in any way.

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5

Thanks both, the first reply is a very good point. Let me ask a slightly different question :slight_smile:

I have a hot tub, with an air source heat pump (ASHP). That ASHP has two modes, heat and cool. I'd like to use a standard virtual thermostat to allow me to set two temps (using ActionTiles):

  1. The cool set point (8C)
  2. The heat set point (38C)

The rest of the logic of the stat will be controlled by me using some simple IF statements in WebCore. I can control the mode, the operating state etc. This would allow me to change the mode of the tub and to have an easily accessible cold and hot temp.

I'm wondering if there is a very quick way to change the groovy to let me do this. I simply want a dumb virtual thermostat that lets me do this. Which leads me nicely to response No 3 @kevin this looks exactly like what I'm looking for :crossed_fingers:

6

Related to a thermostat’s normal workings you have your heat and cool set points transposed though - you normally want to ‘heat’ when the temperature is too low and ‘cool’ when the temperature is too high. This is how the call for heat and call for cool demands are generated. Hence coolsetpoint is always higher by a margin from heatsetpoint which avoids both being called for simultaneously and a heating overshoot generating a cooling demand or vica versa

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7

Yep. all agreed. Thanks for the input to date.

I guess I was curious to understand if I could use the thermostat driver for a slightly different use case. In my case the need to store two temperatures, and ideally change them using something like ActionTiles.

I'm no coder but I might have a nose at the original driver and see if I can dumb it down:

I'll provide any progress back here. Thanks again folks.

8

I have sent you a link to download my version Paul.

I would keep the two setpoints the right way around though - you can still store and use them within rules.